Spark-plug.



H. F. PARKER.

Patented Fab. 23, w09.

ATTORNEY UNITED srrirnsuiiirnnfr oni-ues.

HENRY F. PARKER, OF MONTCLAIR, NEW JERSEY, ASSIGNOR T() YOULE T. FRAZEE, OF MONTCLAIR, NEW JERSEY.

SPARK-PLUG.

Specification of Letters Patent.

Patented Feb. 23, 1909.

Application filed December 1, i966. Serial No. 345,930.

`citizen of the United States, and resident of Montclair, Essex county, New Jersey, have invented certain new and useful linrovements in Spark-Plugs, ot which the ollowino' is a specification.

The o ject of luy-invention is to provide ug or igniter for internal combustion, produce effective sparking, and be capable of withstanding the work to which it is subjected.

My invention comprises the novel details of improvement and arrangement of parts that will be more fully hereinafter' set forth i and then pointed out in the claims.

Reference is to be had to the accompany-- in drawings forming part hereof, whereinigure 1 is a side view of a spark plug embodying my improvements, Fig. 2 is a vertical section thereof, Fig. 3 is an end view thereof, Fig. 4 is anenlarged detail View of part of the plug, showing the ball engaging insulation, Fig. 5 is a vertical section thereof, Fig. 6 is an end view of the plug, showing a plurality of terminal bars, ig. Z is a detail sectional view, showing a modification. v

In the accompanyin drawings, in which similar numerals of re erence indicate corre- Sponding parts in the several views, the numeral 1 indicates the metal body portion of the 1u which is shown as hollow and provlde with external threads la for connection with an engine, and serves as a ground for the electric current, and at its ,open end said body l is shown provided with a cross member or terminal 2 which may be made integral with said body by cutting away the metal of the` body at its extremity, leaving a space 3 leading to the bore 1* of said body, the inner surface 2 of said terminal being shown concave. At 5 is a meta] rod or conductor passing through the bore 1b of the body 1 and insulated therefrom by suitable insulation 6 that extends within the bodyand projects upwardly therefrom. The insulation 6 may be made in a. single piece of `suitable material, such as porcelain, or may be Vmade of disks ofzmica held tightly together, as illustrated in Fig. 7. The insulation 6 has an annular enlargement 6 to bear against an internal annular shoulder Swithin body 1, and may be held in place by a nut 9 screwing into threads 1() within the cuter part of the bore ot' body 1 to do tachably hold the insulation 6 in place. und by preference I interpose resilient insulation 1l, such as asbestos, between the enlargement 6H, the shoulder 8, and the n ut 9 where a friable insulating piece 6, such as porcelain, is used. The insulation 6 is shown of less ydiameter than the bore lb to provide a space between the insulator and body 1 to resist short circuiting by carbon or soot deposit on the walls. The rod 5 is shown provided with a head 5a located within the depression or bore 6b in the ii'isulating member 6, resilient insulatiuu, at i2, such as asbestos being preierl ably interposed in the bottom of depression or ore 6b against which the head 5 bears, which insulation, by beinfr made of asbestos, will resist heat, prevent tie escape of gases, and provide against breakage of the parts by expansion.

The end of the insulating member 6 within the bore 1b of body 1, that projects beyond the head 5 of rod 5, is provided with one or more transverse cuts or depressions, at 6C, to provide lateral openings in the bore 6b. The rod 5 may be secured in place within the insulating member 6 by a cap 13 having internal threads engaging the threads upon rod 5, so that when screwed down said cap will bear against the insulation 6 and draw the head 5 of rod 5 firmly to its seat against the insulation 1.2. A nut 14e on the threaded part of rod 5 permits connection of said rod with a circuit wire. I

At l15 is a Inova-ble metal member, shown in the form ot a bali, interposed between the head 5a of rod 5 and the cross bar or terminal 2 of body .1, and iorn'iing a portion of the circuit of the plug and from which the sparks will jump to the terminal 2. Said ball iits somewhat loosely between the end of i nsulating member 6 or conductor 5, and the terminal 2 so as to more about to decrease the tendency :For the deposit of soot or carbon on the ball and the parts with which it makes Contact, and when said ball fits against 0r into the open end of the insulating meinber 6 the depressions or cuts 6 permit gases `to pass behind the ball into the bore or space `the ball in position in line with conductor or the terminal 2 when the plug is held in the F position shown in the drawings, or with the l ball hanging down, I provide insulation 16 on the cross bar or terminal 2, which may be a piece of magncsia rod, lavite, or other suitl able heat-resisting insulation, inserted in a hole 17 in terminal 2, and which will project l a suitable distance inwardly from terminal Q so that the ball 15 will remain at a suitable distance from terminal 2, providing a gap or space between them, and the ball may then bear more closely against the adjacent end of insulating member (j, and the latter keeps rod 5.

The diameter of. ball 15 is such, preferably, as to permit it to have some free motion between the insulator 16 and the insulating member and yet the ball need not be in contact with the head 5a of rod 5 the ball being shown in Fig. 5 as of such size as to enter the depression 1n insulating member to hold the ball in line with conductor 5.

l-Vhen the current flows it will ass from rod 5 to the ball 15 and thence wi l jump to the terminal 2, and may also um between the ball and rod 5, and usually will produce several sparks which will play between the ball and terminal 2, or rod 5, or both, and the independent movement of the ball will serve to assist in keeping its surface and the surfaces it engages more or less clear from the deposit of soot and carbon. Adjustment can be made between the ball and rod 5 by changing the thickness of the insulation 11 or 12, or both.

In Fig. 7 the terminal 2 instead of being made integral with the body 1 is shown as made in a se arate piece, which may be in the nature oi) a plurality of arms having spaces between them and provided with threads 1c to engage corresponding threads within the bore 1b of the body 1, and thereby adjustment may also be made between the ba l and terminal 2. In this figure also the insulating member 6, which may be of mica as before stated, is pressed a 'ainst by the head 5a, and the end of the atter may be curved, as at 5", where it opposes and receives ball 15, to keep the ball in position at the end of rod 5.

In all the views. the sparks will jump to or from the ball in whatever position the plug be held, for if the plug be inverted with the ball extending upwardly the sparks will jump from the ball to terminal 2, and if the plug, arranged as in Figs. 1 and 2, has the ball depending the sparks will jump from rod 5 to the ball as well as to terminal 2. In all cases the opening 3 and the internal bores permit gases that enter the plug. to be ignited by the jump spark.

Having now described my invention what I claim is:

1. A spark` plug comprising a hollow body provided with a terminal at one end, an insulatingl member within the body provided with a bore, a rod within said bore, insulating means between the rod and said iusulat ing member and between said member and said body making gas-tight joints therebetween, and a movable metallic member between said rod and said terminal, the distance between the rod and the tern'iinal being greater than thtl diaireterof said movable 75 member, and means for detaehably securing said insulating member within said body.

2. A spark plug comprising a hollow body provided with a terminal at one end, an insulating member within said body having a bore and a depression in its end leading to said bore, a conductor within said bore having its terminal end located within said depression, a movable member located between the end of said insulating member and said terminal and of less diameter than the distance between the conductor and said termi nal, means to make gas-tight joints between said body and the insulating member and between said member and said conductor, and means to detach-ably secure said insulating member within said body.

3. A spark plug comprising a hollow body having a terminal at one end provided with an inwardly projecting insulating piece, a conductor within the body terminating at a distance from said insulating piece, means for insulating said conductor from said body, and a movable conductor member located between said insulating piece and said conductor of less diameter than the distance between said conductor and said insulating piece.

4. A spark plug comprising a hollow bod having a terminal at one en provided wit i an inwardly extending insulating piece, an insulating member within said body provided with a bore and having a depression at its end, a conductor within said member having its end at a distance from said insulating piece, and a metal ball located between said conductor and said insulating piece, whereby the latter maintains the ball out of contact With said terminal.

5. A spark plug comprising a hollow body having a cross-bar terminal at one .end integral therewith and extending across in line with the open end of said body providing an open space leading to the bore of said body,

a conductor within said body having its end located at a distance from said terminal, means for insulating said conductor from said body, and a metal ball interposed between said terminal and said conductor.

6. A spark plug comprising a hollow body provided with a terminal at one end having an inwardly extending insulating piece, a conductor within said body,- an insulating member within said body having a bore and a depression receiving said conductor, and a metal ball loe-Med between the end of said insulating member and Said insulating piece, said ba ll being of suoli size as to partly enter the depression of said insulating member to hold the ball in line with said conductor, und menus for securing said insulating inembel Within Suid body.

7. A Simi-li' plug` including.,r two terminals. and u movable bell intermediate the two and normally iu engagement with but one of them.

S. A spurl; plug, including a body having ille inner' end thereof substantially hemispherienl und provided with a plurality of slots subdividing said inner end into bars forming an open cage, an electrode extending in proximity to said cage, and a movable body Within said cage and supported thereby but out of engagement with said electrode.

9. A spark plug comprising a hollow body provided with :1` terminal at one end, an insulating member within the bod provided with a bore, a rod Within said ore and a movable metallic member between said rod and said terminal, the distance between the rod and the terminal being greater than the diameter of said movable member.

HENRY F. PARKER.

Vlitnesses:

T. F. BOURNE, F. SWINTON. 

